DC/UCF Execution Mode in the CICS Environment

The DC/UCF region runs independently of the CICS monitor, but CICS programs use CA IDMS central version database management services.
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The DC/UCF region runs independently of the CICS monitor, but CICS programs use CA IDMS central version database management services.
The following diagram shows the CICS monitor and the DC/UCF system:
┌───────────────────────────────────────────────────┐ │                   SUPERVISOR                      │ ├──────────────────────┬────────────────────────────┤ │ ┌────────────┐       │    ┌──────────────┐        │ │ │   DC/UCF   │       │    │   CICS       │        │ │ │ (Main task)│       │    │ (Main task)  │        │ │ │            │       │    │              │        │ │ │            │       │    ├──────────────┤        │ │ │            │       │    │  IDMSINTC    │        │ │ │            │       │    │    CICS      │        │ │ │            │       │    │  RESIDENT    │        │ │ │            │       │    │     TX       │        │ │ │            │       │    └──────────────┘        │ │ │            │       │                            │ │ └────────────┘       │                            │ │                      │                            │ │      P1              │                P2          │ └──────────────────────┴────────────────────────────┘
To operate CICS with DC/UCF
  1. Start up the DC/UCF system.
  2. Start up CICS following standard CICS operating procedures.
Dispatch priorities
You should assign DC/UCF a higher dispatching priority than CICS. If CICS has a higher priority, you run the risk, in a busy system, of starting many more CICS tasks and of binding the DC/UCF transactions without giving DC/UCF an opportunity to finish what was started. By having DC/UCF at a higher dispatching priority, work is more likely to be completed in an efficient first in - first out (FIFO) method. In addition, there is less likelihood of exceeding the MAXERUS task parameter limit and less likelihood of exceeding the MAXTASKS parameter limit on CICS when all the CICS tasks are waiting on CA IDMS requests to finish.